Maintained by: NLnet Labs

edns-buffer-size

T.Suzuki
Thu Sep 7 09:45:51 CEST 2017


On Fri, 1 Sep 2017 17:04:53 -0300
Eduardo Schoedler via Unbound-users <unbound-users at unbound.net> wrote:

> And for IPv6 header?

On general Ethernet,

1452 = 1500-40-8

However, some people who do not believe PMTUD are using 1280 as minimum MTU.

So,

1232 = 1280-40-8

will be more safety.

But I do not want use EDNS0. It is very wastefull for other than DNSSEC user.

I want to enable DO bit. Can I do with Unbound? (However I know it's "MUST" by RFC.)

> 2017-09-01 11:46 GMT-03:00 T.Suzuki via Unbound-users
> <unbound-users at unbound.net>:
> > unbound.conf
> > # EDNS reassembly buffer to advertise to UDP peers (the actual buffer
> > # is set with msg-buffer-size). 1480 can solve fragmentation (timeouts)
> > edns-buffer-size:
> >
> > Why does this comment recommend
> >  1480 = 1500 - 20 ? (UDP datagram size over IPv4)
> >
> > Why is this value not to become
> >  1472 = 1500 - 20 - 8 ? (UDP payload size over IPv4)
> >
> > Or, Is this a value of another meaning?
> >
> > (I verified that the edns-buffer-size is used for udp payload size of EDNS0.)
> >
> > --
> > ------------------------------------------------------------------------------
> > T.Suzuki
> 
> 
> 
> -- 
> Eduardo Schoedler
> 


-- 
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T.Suzuki